We retrospectively analyzed 98 consecutive patients who underwent aortic surgery with
deep hypothermic circulatory arrest between 2010 and 2014. We evaluated lowest temperature, absolute decrease in temperature, and
rewarming rate. Univariate and multivariate regression were used to determine relationships between temperature, clinical characteristics, and measures of postoperative
bleeding.
RESULTS: The mean age of patients was 60.5 ± 15.1 years, with 64.3% male and 60% Caucasian. The lowest temperatures recorded were 13.5 ± 4.6°C at the bypass circuit. Change in hematocrit was associated with ethnicity, preoperative hematocrit, and
rewarming rate.
Chest tube output was associated with body mass index, preoperative platelet count, prior cardiac surgery,
cardiopulmonary bypass (CPB) duration, intraoperative blood product transfusion, lowest surface temperature, and change in surface temperature. Postoperative packed
red blood cell transfusion was associated with ejection fraction,
chronic obstructive pulmonary disease (
COPD), platelet count, partial thromboplastin time, CPB duration, and lowest blood temperature. Fresh frozen plasma transfusion correlated with
COPD, CPB duration, and final blood temperature.
Platelet transfusion correlated with body mass index and preoperative platelet count. Unplanned reoperation for
bleeding was associated with final temperature and change in temperature.
CONCLUSION: We found no consistent associations between intraoperative temperature and indicators of
bleeding. Intraoperative cooling strategies should be based on optimal end-organ protection rather than fear of postoperative
bleeding;
rewarming strategies may ameliorate the risk of coagulopathy.